prevent bizare half open state. (#1754)

* attempt path timeout bullshittery fix

* make sure ServiceInfo always has its address set up

* do not copy intros in constuctor, ammend logging and
add assert

llarp/path/pathbuilder.hpp

@@ -110,7 +110,7 @@ namespace llarp
       llarp_time_t
       Now() const override;
 
-      void
+      virtual void
       Tick(llarp_time_t now) override;
 
       void

llarp/service/endpoint.cpp

@@ -470,6 +470,7 @@ namespace llarp
       if (itr == Sessions().end())
         return false;
       si = itr->second.remote;
+      si.UpdateAddr();
       return true;
     }
 
@@ -1100,13 +1101,14 @@ namespace llarp
 
     bool
     Endpoint::HandleDataMessage(
-        path::Path_ptr, const PathID_t from, std::shared_ptr<ProtocolMessage> msg)
+        path::Path_ptr p, const PathID_t from, std::shared_ptr<ProtocolMessage> msg)
     {
       PutSenderFor(msg->tag, msg->sender, true);
       Introduction intro = msg->introReply;
       if (HasInboundConvo(msg->sender.Addr()))
       {
         intro.pathID = from;
+        intro.router = p->Endpoint();
       }
       PutReplyIntroFor(msg->tag, intro);
       ConvoTagRX(msg->tag);

llarp/service/intro.hpp

@@ -13,7 +13,7 @@ namespace llarp
   {
     struct Introduction
     {
-      PubKey router;
+      RouterID router;
       PathID_t pathID;
       llarp_time_t latency = 0s;
       llarp_time_t expiresAt = 0s;

llarp/service/outbound_context.cpp

@@ -54,7 +54,7 @@ namespace llarp
       return true;
     }
 
-    constexpr auto OutboundContextNumPaths = 2;
+    constexpr auto OutboundContextNumPaths = 4;
 
     OutboundContext::OutboundContext(const IntroSet& introset, Endpoint* parent)
         : path::Builder{parent->Router(), OutboundContextNumPaths, parent->numHops}
@@ -64,12 +64,17 @@ namespace llarp
         , currentIntroSet{introset}
 
     {
+      assert(not introset.intros.empty());
       updatingIntroSet = false;
-      for (const auto& intro : introset.intros)
+
+      // pick random first intro
+      auto it = introset.intros.begin();
+      if (introset.intros.size() > 1)
       {
-        if (m_NextIntro.latency == 0s or m_NextIntro.latency > intro.latency)
-          m_NextIntro = intro;
+        CSRNG rng{};
+        it += std::uniform_int_distribution<size_t>{0, introset.intros.size() - 1}(rng);
       }
+      m_NextIntro = *it;
       currentConvoTag.Randomize();
       lastShift = Now();
       // add send and connect timeouts to the parent endpoints path alignment timeout
@@ -333,6 +338,7 @@ namespace llarp
       Encrypted<64> tmp;
       tmp.Randomize();
       SendPacketToRemote(tmp, ProtocolType::Control);
+      m_LastKeepAliveAt = Now();
     }
 
     bool
@@ -348,7 +354,10 @@ namespace llarp
         // expunge
         SharedSecret discardme;
         if (not m_DataHandler->GetCachedSessionKeyFor(currentConvoTag, discardme))
+        {
+          LogError(Name(), " no cached key after sending intro, we are in a fugged state, oh no");
           return true;
+        }
       }
 
       if (m_GotInboundTraffic and m_LastInboundTraffic + sendTimeout <= now)
@@ -404,21 +413,33 @@ namespace llarp
         m_ReadyHooks.clear();
       }
 
-      if (m_LastInboundTraffic > 0s and lastGoodSend > 0s
-          and now >= sendTimeout + m_LastInboundTraffic)
-        return true;
-
       const auto timeout = std::max(lastGoodSend, m_LastInboundTraffic);
       if (lastGoodSend > 0s and now >= timeout + (sendTimeout / 2))
       {
         // send a keep alive to keep this session alive
         KeepAlive();
         if (markedBad)
+        {
+          LogWarn(Name(), " keepalive timeout hit");
           return true;
+        }
+      }
+
+      // check for half open state where we can send but we get nothing back
+      if (m_LastInboundTraffic == 0s and now - createdAt > connectTimeout)
+      {
+        LogWarn(Name(), " half open state, we can send but we got nothing back");
+        return true;
       }
       // if we are dead return true so we are removed
-      return timeout > 0s ? (now >= timeout && now - timeout > sendTimeout)
-                          : (now >= createdAt && now - createdAt > connectTimeout);
+      const bool removeIt = timeout > 0s ? (now >= timeout && now - timeout > sendTimeout)
+                                         : (now >= createdAt && now - createdAt > connectTimeout);
+      if (removeIt)
+      {
+        LogInfo(Name(), " session is stale");
+        return true;
+      }
+      return false;
     }
 
     void
@@ -584,6 +605,25 @@ namespace llarp
       }
     }
 
+    bool
+    OutboundContext::ShouldKeepAlive(llarp_time_t now) const
+    {
+      const auto SendKeepAliveInterval = sendTimeout / 2;
+      if (not m_GotInboundTraffic)
+        return false;
+      if (m_LastInboundTraffic == 0s)
+        return false;
+      return (now - m_LastKeepAliveAt) >= SendKeepAliveInterval;
+    }
+
+    void
+    OutboundContext::Tick(llarp_time_t now)
+    {
+      path::Builder::Tick(now);
+      if (ShouldKeepAlive(now))
+        KeepAlive();
+    }
+
     bool
     OutboundContext::HandleHiddenServiceFrame(path::Path_ptr p, const ProtocolFrame& frame)
     {

llarp/service/outbound_context.hpp

@@ -23,6 +23,9 @@ namespace llarp
 
       ~OutboundContext() override;
 
+      void
+      Tick(llarp_time_t now) override;
+
       util::StatusObject
       ExtractStatus() const;
 
@@ -129,6 +132,9 @@ namespace llarp
       void
       KeepAlive();
 
+      bool
+      ShouldKeepAlive(llarp_time_t now) const;
+
       const IntroSet&
       GetCurrentIntroSet() const
       {
@@ -170,6 +176,7 @@ namespace llarp
       bool sentIntro = false;
       std::vector<std::function<void(OutboundContext*)>> m_ReadyHooks;
       llarp_time_t m_LastIntrosetUpdateAt = 0s;
+      llarp_time_t m_LastKeepAliveAt = 0s;
     };
   }  // namespace service
 

llarp/service/sendcontext.hpp

@@ -45,7 +45,7 @@ namespace llarp
       llarp_time_t lastGoodSend = 0s;
       const llarp_time_t createdAt;
       llarp_time_t sendTimeout = path::build_timeout;
-      llarp_time_t connectTimeout = path::build_timeout;
+      llarp_time_t connectTimeout = path::build_timeout * 2;
       llarp_time_t shiftTimeout = (path::build_timeout * 5) / 2;
       llarp_time_t estimatedRTT = 0s;
       bool markedBad = false;